Hello!
Let's begin by doing a summation of torques, placing the pivot point at the attachment point of the rod to the wall.
We have two torques acting on the rod:
- Force of gravity at the center of mass (d = 0.700 m)
- VERTICAL component of the tension at a distance of 'L' (L = 2.200 m)
Both of these act in opposite directions. Let's use the equation for torque:
Doing the summation using their respective lever arms:
Our unknown is 'theta' - the angle the string forms with the rod. Let's use right triangle trig to solve:
Now, let's solve for 'T'.
Plugging in the values: